indirect_vertex_array.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

    else {
	arrays->DrawArrays = emit_DrawArrays_none;
	arrays->DrawElements = emit_DrawElements_none;
    }

    arrays->array_info_cache_valid = GL_TRUE;
}


/**
 * Emit a \c glDrawArrays command using the "none" protocol.  That is,
 * emit immediate-mode commands that are equivalent to the requiested
 * \c glDrawArrays command.  This is used with servers that don't support
 * the OpenGL 1.1 / EXT_vertex_arrays DrawArrays protocol or in cases where
 * vertex state is enabled that is not compatible with that protocol.
 */
void
emit_DrawArrays_none( GLenum mode, GLint first, GLsizei count )
{
    __GLXcontext *gc = __glXGetCurrentContext();
    const __GLXattribute * state = 
       (const __GLXattribute *)(gc->client_state_private);
    struct array_state_vector * arrays = state->array_state;

    size_t single_vertex_size;
    GLubyte * pc;
    unsigned  i;
    static const uint16_t begin_cmd[2] = { 8, X_GLrop_Begin };
    static const uint16_t end_cmd[2]   = { 4, X_GLrop_End };


    single_vertex_size = calculate_single_vertex_size_none( arrays );

    pc = gc->pc;

    (void) memcpy( pc, begin_cmd, 4 );
    *(int *)(pc +  4) = mode;

    pc += 8;

    for ( i = 0 ; i < count ; i++ ) {
	if ( (pc + single_vertex_size) >= gc->bufEnd ) {
	    pc = __glXFlushRenderBuffer(gc, pc);
	}

	pc = emit_element_none( pc, arrays, first + i );
    }

    if ( (pc + 4) >= gc->bufEnd ) {
	pc = __glXFlushRenderBuffer(gc, pc);
    }

    (void) memcpy( pc, end_cmd, 4 );
    pc += 4;

    gc->pc = pc;
    if ( gc->pc > gc->limit ) {
	(void) __glXFlushRenderBuffer(gc, gc->pc);
    }
}


/**
 * Emit the header data for the GL 1.1 / EXT_vertex_arrays DrawArrays
 * protocol.
 * 
 * \param gc                    GLX context.
 * \param arrays                Array state.
 * \param elements_per_request  Location to store the number of elements that
 *                              can fit in a single Render / RenderLarge
 *                              command.
 * \param total_request         Total number of requests for a RenderLarge
 *                              command.  If a Render command is used, this
 *                              will be zero.
 * \param mode                  Drawing mode.
 * \param count                 Number of vertices.
 * 
 * \returns
 * A pointer to the buffer for array data.
 */
static GLubyte *
emit_DrawArrays_header_old( __GLXcontext * gc,
			    struct array_state_vector * arrays,
			    size_t * elements_per_request,
			    unsigned int * total_requests,
			    GLenum mode, GLsizei count )
{
    size_t command_size;
    size_t single_vertex_size;
    const unsigned header_size = 16;
    unsigned  i;
    GLubyte * pc;


    /* Determine the size of the whole command.  This includes the header,
     * the ARRAY_INFO data and the array data.  Once this size is calculated,
     * it will be known whether a Render or RenderLarge command is needed.
     */

    single_vertex_size = 0;
    for ( i = 0 ; i < arrays->num_arrays ; i++ ) {
	if ( arrays->arrays[i].enabled ) {
	    single_vertex_size += __GLX_PAD( arrays->arrays[i].element_size );
	}
    }

    command_size = arrays->array_info_cache_size + header_size 
      + (single_vertex_size * count);


    /* Write the header for either a Render command or a RenderLarge
     * command.  After the header is written, write the ARRAY_INFO data.
     */

    if ( command_size > gc->maxSmallRenderCommandSize ) {
	/* maxSize is the maximum amount of data can be stuffed into a single
	 * packet.  sz_xGLXRenderReq is added because bufSize is the maximum
	 * packet size minus sz_xGLXRenderReq.
	 */
	const size_t maxSize = (gc->bufSize + sz_xGLXRenderReq)
	  - sz_xGLXRenderLargeReq;
	unsigned vertex_requests;


	/* Calculate the number of data packets that will be required to send
	 * the whole command.  To do this, the number of verticies that
	 * will fit in a single buffer must be calculated.
	 * 
	 * The important value here is elements_per_request.  This is the
	 * number of complete array elements that will fit in a single
	 * buffer.  There may be some wasted space at the end of the buffer,
	 * but splitting elements across buffer boundries would be painful.
	 */

	elements_per_request[0] = maxSize / single_vertex_size;

	vertex_requests = (count + elements_per_request[0] - 1)
	  / elements_per_request[0];
	  
	*total_requests = vertex_requests + 1;


	__glXFlushRenderBuffer(gc, gc->pc);

	command_size += 4;

	pc = ((GLubyte *) arrays->array_info_cache) - (header_size + 4);
	*(uint32_t *)(pc +  0) = command_size;
	*(uint32_t *)(pc +  4) = X_GLrop_DrawArrays;
	*(uint32_t *)(pc +  8) = count;
	*(uint32_t *)(pc + 12) = arrays->enabled_client_array_count;
	*(uint32_t *)(pc + 16) = mode;

	__glXSendLargeChunk( gc, 1, *total_requests, pc,
			     header_size + 4 + arrays->array_info_cache_size );

	pc = gc->pc;
    }
    else {
	if ( (gc->pc + command_size) >= gc->bufEnd ) {
	    (void) __glXFlushRenderBuffer(gc, gc->pc);
	}

	pc = gc->pc;
	*(uint16_t *)(pc +  0) = command_size;
	*(uint16_t *)(pc +  2) = X_GLrop_DrawArrays;
	*(uint32_t *)(pc +  4) = count;
	*(uint32_t *)(pc +  8) = arrays->enabled_client_array_count;
	*(uint32_t *)(pc + 12) = mode;

	pc += header_size;

	(void) memcpy( pc, arrays->array_info_cache,
		       arrays->array_info_cache_size );
	pc += arrays->array_info_cache_size;

	*elements_per_request = count;
	*total_requests = 0;
    }


    return pc;
}


/**
 */
void
emit_DrawArrays_old( GLenum mode, GLint first, GLsizei count )
{
    __GLXcontext *gc = __glXGetCurrentContext();
    const __GLXattribute * state = 
       (const __GLXattribute *)(gc->client_state_private);
    struct array_state_vector * arrays = state->array_state;

    GLubyte * pc;
    size_t elements_per_request;
    unsigned total_requests = 0;
    unsigned i;
    size_t total_sent = 0;


    pc = emit_DrawArrays_header_old( gc, arrays, & elements_per_request,
				     & total_requests, mode, count);

    
    /* Write the arrays.
     */

    if ( total_requests == 0 ) {
	assert( elements_per_request >= count );

	for ( i = 0 ; i < count ; i++ ) {
	    pc = emit_element_old( pc, arrays, i + first );
	}

	assert( pc <= gc->bufEnd );

	gc->pc = pc;
	if ( gc->pc > gc->limit ) {
	    (void) __glXFlushRenderBuffer(gc, gc->pc);
	}
    }
    else {
	unsigned req;


	for ( req = 2 ; req <= total_requests ; req++ ) {
	    if ( count < elements_per_request ) {
		elements_per_request = count;
	    }

	    pc = gc->pc;
	    for ( i = 0 ; i < elements_per_request ; i++ ) {
		pc = emit_element_old( pc, arrays, i + first );
	    }

	    first += elements_per_request;

	    total_sent += (size_t) (pc - gc->pc);
	    __glXSendLargeChunk( gc, req, total_requests, gc->pc,
				 pc - gc->pc );

	    count -= elements_per_request;
	}
    }
}


void
emit_DrawElements_none( GLenum mode, GLsizei count, GLenum type,
			const GLvoid *indices )
{
    __GLXcontext *gc = __glXGetCurrentContext();
    const __GLXattribute * state = 
       (const __GLXattribute *)(gc->client_state_private);
    struct array_state_vector * arrays = state->array_state;
    static const uint16_t begin_cmd[2] = { 8, X_GLrop_Begin };
    static const uint16_t end_cmd[2]   = { 4, X_GLrop_End };

    GLubyte * pc;
    size_t single_vertex_size;
    unsigned  i;


    single_vertex_size = calculate_single_vertex_size_none( arrays );


    if ( (gc->pc + single_vertex_size) >= gc->bufEnd ) {
	gc->pc = __glXFlushRenderBuffer(gc, gc->pc);
    }

    pc = gc->pc;

    (void) memcpy( pc, begin_cmd, 4 );
    *(int *)(pc +  4) = mode;

    pc += 8;

    for ( i = 0 ; i < count ; i++ ) {
	unsigned  index = 0;

	if ( (pc + single_vertex_size) >= gc->bufEnd ) {
	    pc = __glXFlushRenderBuffer(gc, pc);
	}

	switch( type ) {
	case GL_UNSIGNED_INT:
	    index = (unsigned) (((GLuint *) indices)[i]);
	    break;
	case GL_UNSIGNED_SHORT:
	    index = (unsigned) (((GLushort *) indices)[i]);
	    break;
	case GL_UNSIGNED_BYTE:
	    index = (unsigned) (((GLubyte *) indices)[i]);
	    break;
	}
	pc = emit_element_none( pc, arrays, index );
    }

    if ( (pc + 4) >= gc->bufEnd ) {
	pc = __glXFlushRenderBuffer(gc, pc);
    }

    (void) memcpy( pc, end_cmd, 4 );
    pc += 4;

    gc->pc = pc;
    if ( gc->pc > gc->limit ) {
	(void) __glXFlushRenderBuffer(gc, gc->pc);
    }
}


/**
 */
void
emit_DrawElements_old( GLenum mode, GLsizei count, GLenum type,
		       const GLvoid *indices )
{
    __GLXcontext *gc = __glXGetCurrentContext();
    const __GLXattribute * state = 
       (const __GLXattribute *)(gc->client_state_private);
    struct array_state_vector * arrays = state->array_state;

    GLubyte * pc;
    size_t elements_per_request;
    unsigned total_requests = 0;
    unsigned i;
    unsigned req;
    unsigned req_element=0;


    pc = emit_DrawArrays_header_old( gc, arrays, & elements_per_request,
				     & total_requests, mode, count);

    
    /* Write the arrays.
     */

    req = 2;
    while ( count > 0 ) {
	if ( count < elements_per_request ) {
	    elements_per_request = count;
	}

	switch( type ) {
	case GL_UNSIGNED_INT: {
	    const GLuint   * ui_ptr = (const GLuint   *) indices + req_element;

	    for ( i = 0 ; i < elements_per_request ; i++ ) {
		const GLint index = (GLint) *(ui_ptr++);
		pc = emit_element_old( pc, arrays, index );
	    }
	    break;
	}
	case GL_UNSIGNED_SHORT: {
	    const GLushort * us_ptr = (const GLushort *) indices + req_element;

	    for ( i = 0 ; i < elements_per_request ; i++ ) {
		const GLint index = (GLint) *(us_ptr++);
		pc = emit_element_old( pc, arrays, index );
	    }
	    break;
	}
	case GL_UNSIGNED_BYTE: {
	    const GLubyte  * ub_ptr = (const GLubyte  *) indices + req_element;

	    for ( i = 0 ; i < elements_per_request ; i++ ) {
		const GLint index = (GLint) *(ub_ptr++);
		pc = emit_element_old( pc, arrays, index );
	    }
	    break;
	}
	}

	if ( total_requests != 0 ) {
	    __glXSendLargeChunk( gc, req, total_requests, gc->pc,
				 pc - gc->pc );
	    pc = gc->pc;
	    req++;
	}

	count -= elements_per_request;
	req_element += elements_per_request;
    }


    assert( (total_requests == 0) || ((req - 1) == total_requests) );

    if ( total_requests == 0 ) {
	assert( pc <= gc->bufEnd );

	gc->pc = pc;
	if ( gc->pc > gc->limit ) {
	    (void) __glXFlushRenderBuffer(gc, gc->pc);
	}
    }
}


/**
 * Validate that the \c mode parameter to \c glDrawArrays, et. al. is valid.
 * If it is not valid, then an error code is set in the GLX context.
 * 
 * \returns
 * \c GL_TRUE if the argument is valid, \c GL_FALSE if is not.
 */
static GLboolean
validate_mode(__GLXcontext *gc, GLenum mode)
{
    switch(mode) {
      case GL_POINTS:
      case GL_LINE_STRIP:
      case GL_LINE_LOOP:
      case GL_LINES:
      case GL_TRIANGLE_STRIP:
      case GL_TRIANGLE_FAN:
      case GL_TRIANGLES:
      case GL_QUAD_STRIP:
      case GL_QUADS:
      case GL_POLYGON:
	break;
      default:
        __glXSetError(gc, GL_INVALID_ENUM);
        return GL_FALSE;
    }
    
    return GL_TRUE;
}


/**
 * Validate that the \c count parameter to \c glDrawArrays, et. al. is valid.
 * A value less than zero is invalid and will result in \c GL_INVALID_VALUE
 * being set.  A value of zero will not result in an error being set, but
 * will result in \c GL_FALSE being returned.
 * 
 * \returns
 * \c GL_TRUE if the argument is valid, \c GL_FALSE if it is not.
 */
static GLboolean
validate_count(__GLXcontext *gc, GLsizei count)
{
    if (count < 0) {
	__glXSetError(gc, GL_INVALID_VALUE);
    }

    return (count > 0);
}


/**
 * Validate that the \c type parameter to \c glDrawElements, et. al. is
 * valid.  Only \c GL_UNSIGNED_BYTE, \c GL_UNSIGNED_SHORT, and
 * \c GL_UNSIGNED_INT are valid.
 *
 * \returns
 * \c GL_TRUE if the argument is valid, \c GL_FALSE if it is not.
 */
static GLboolean validate_type(__GLXcontext *gc, GLenum type)
{
    switch( type ) {
    case GL_UNSIGNED_INT:
    case GL_UNSIGNED_SHORT:
    case GL_UNSIGNED_BYTE:
	return GL_TRUE;
     default:
	__glXSetError(gc, GL_INVALID_ENUM);
	return GL_FALSE;